Diagnosis:Nocloa plagiata is an easily recognized
species from the southwestern United States. The general color of the
moth is brown. The maculation in the forewing is distinct and will immediately
separate plagiata from the other two species in the genus, rivulosa
and pallens. In the forewing there is a dark brown dash or patch
in the basal area at the inner margin. The antemedial line is dull white,
slanting outward from the costa to the inner margin. There is a dark brown
blurred claviform spot running from the antemedial line to medial line.
The medial line is located far closer to the postmedial than to the antemedial
line. Both the reniform spot and the orbicular spot are present, if not
prominent. The postmedial line curves around the reniform spot and then
swings back toward the base of the wing, coming close the inception of
the antemedial line on the inner margin. There is a dark brown costal
triangle on the subterminal line, followed just below it by a small dark
brown triangle. The terminal area has a slightly grayish tinge to it.
The hindwing dorsally has a faint postmedial line and a diffuse, but larger
subterminal band. The male and female genitalia are as in described in
the generic description and shown in the plate figures. Wing length: mean
= 13.17 mm, standard deviation = 0.80 mm, n = 10.

Adults have been collected most in August and September. However there
is a single specimen from the Big Bend region of western Texas collected
in May.

Distribution: This species occurs in southwestern Texas,
southern New Mexico and the southern half of Arizona as far west and north
as Yavapai and Mohave Counties. The species undoubtedly occurs in northern
Mexico as well, but has not yet been collected there. Females on the whole
are slightly larger and darker than males, but not greatly so. There is
little if any variation in this species.